In auger-type snow plows, an auger housing is mounted to a vehicle body frame including travel device, such that the auger housing can be raised and lowered and made to roll. The auger housing includes an auger. An auger snow plow can scrape up snow by means of a front auger while traveling forward, and can disperse the scraped up snow far away by means of a blower via a shooter.
A snow plow including an auger employs a system for varying the height of the auger housing in accordance with the conditions of the snow plowing work. It is more efficient to move the snow plow when the bottom surface of the auger housing has been raised. It is more efficient to plow snow when the bottom surface of the auger housing has been lowered. The height of the auger housing is also often varied according to unevenness in the road surface when snow is plowed.
It is highly inconvenient for a worker to make these variations to the height of the auger housing through manual labor. To alleviate the burden on the worker, the bottom surface of the auger housing can be raised and lowered with a power assist. This feature is disclosed in Japanese Utility Model Application Laid-Open Publication No. 63-136012 (JP-U-S63-136012) and Japanese Patent Application Laid-Open Publication No. 2007-032218 (JP-A-2007-032218).
In the snow plow disclosed in JP-U-S63-136012, the auger housing angle is used to control an angle of inclination detector provided to the auger housing to detect the angle of the auger housing relative to the direction of gravity.
In the snow plow disclosed in JP-A-2007-032218, the raised/lowered angle of the auger housing is controlled due to the angle of the auger housing relative to a travel frame having the travel device being detected by a height position sensor. When a reset switch is turned on by a worker, a control unit controls a raising/lowering drive mechanism so that the control unit adjusts the auger housing to a predetermined height reference position. The term “height reference position” refers to a position where the bottom end of a scraper included in the auger housing comes in contact with a flat surface (the traveled road surface) while the auger housing is in a horizontal state.
When the reset switch is turned on, a display light either flashes or extinguishes to notify the worker that “control is being implemented to return the auger housing to the height reference position.” When the auger housing has then returned to the height reference position, the display light switches to a continuously illuminated state to notify the worker that “the auger housing has returned to the height reference position.”
As described above, in the snow plow disclosed in JP-U-S63-136012, the angle of the auger housing is controlled due to the angle of inclination of the auger housing relative to the direction of gravity being detected. The travel device tilts forward or backward according to the conditions of the road surface being plowed, for example, during the snow plowing work performed by the auger. The auger housing temporarily tilts in the same direction as the travel device at this time.
This feature of JP-U-S63-136012 shall now be considered for application to the feature of JP-A-2007-032218; e.g., the “angle of inclination detector for detecting the angle of inclination relative to the direction of gravity” of JP-U-S63-136012 shall be considered to be replaced by the height position sensor of the snow plow disclosed in JP-A-2007-032218.
With such a configuration, because the travel device tilts forward or backward according to the conditions of the road surface being plowed, for example, during the snow plowing work performed by the auger, the auger housing temporarily tilts in the same direction. The auger housing automatically returns to the height reference position at this time. With this behavior of the auger housing, the display light repeatedly alternates between flashing (or extinguishing) and being fully illuminated. In addition to making snow plowing work more efficient, the goal of automatic orientation control of the auger housing is preferably made more clearly distinguishable by making the illuminated display of the display light clearer. The snow plow disclosed in JP-U-1988-136012 has no such feature.
In view of this, a demand exists for a feature whereby the goal of automatic orientation control of the auger housing during snow plowing work is made more clearly distinguishable by making the illuminated display of the display light clearer.